/*
 * yauosk - Yet Another Useless Operating System Kernel
 *
 * Copyright (c) 2009-2010 Matteo Cicuttin
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 * derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch/x86/machine.h>

#define PIT1_IO_BASE	0x40
#define PIT2_IO_BASE	0x48

#define PIT_INTTC		0x00
#define PIT_ONESHOT		0x02
#define PIT_RATEGEN		0x04
#define PIT_WAVE		0x06
#define	PIT_STROBE_SW	0x08
#define PIT_STROBE_HW	0x0A

#define PIT_C0			0x00
#define PIT_C1			0x40
#define PIT_C2			0x80

#define PIT_16BIT		0x30

#define PIT_FREQ		1193182

#define PIT_DIV(x)		((PIT_FREQ+(x)/2)/(x))

void
pit_8253_init(void)
{
	outb(PIT1_IO_BASE+3, PIT_C0 | PIT_16BIT | PIT_RATEGEN);
	outb(PIT1_IO_BASE, PIT_DIV(100) % 256);
	outb(PIT1_IO_BASE, PIT_DIV(100) / 256);
	printf("8253: configured\n");
}